I′ron.
1. The most useful and abundant of the metals.
Equivalent, 28; symbol,
Fe.; specific gravity, cast-iron, 7.2, wrought-iron, 7; fusing-point, 2,786° Fah. The ores principally worked are the oxides and carbonates, the metal in combination with oxygen, or with oxygen and carbonic acid.
The protoxide is an antidote for arsenic.
The peroxide is an ore, and is used as a pigment (ocher).
The loadstone is a magnetic oxide.
The bi-sulphuret (pyrites) is the bane of the
gold and
silver miner.
Pyrites is now roasted for the production of sulphuric acid.
The protosulphate (green copperas) is used in dyes and inks; and calcined forms
crocus, rouge, cocothar, for polishing.
The useful forms of iron are cast-iron, steel, and wrought-iron.
The former two are compounds of iron and carbon, being carburets or carbides of iron.
Cast-iron has the larger proportion of carbon in its composition.
Wrought-iron is nearly pure iron, but it has generally some traces of carbon, sulphur, and phosphorus.
The less the better, but the two last are hard to eliminate.
Iron was found, so says the chronicle, on
Mount Ida, by the Dactyles, after the burning of the forest by lightning, at a period answering to our 1432 B. C. The
Greeks claim the first discovery of it, of course.
How many centuries it had been used in
China,
India, and
Egypt can hardly be determined.
Moses, who died 20 years before the era assigned, credits one with the inventio who had been dead 2,000 years when he, the great lawgiver, wrote.
Chariots, axes, bedsteads, harrows, weapons of iron, are mentioned in Hebrew history between 1490 B. C. and 1040 B. C. Jeremiah and
Ezekiel speak of iron, and mention two qualities, one of which the latter calls “bright iron,” probably steel.
The same distinction is made by Hesiod (850 B. C.).
Some doubts have been expressed as to the render-
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ing of the Hebrew passage which speaks of
Tubal Cain as an artificer in
iron, and the passage which speaks of the
iron bedstead of Og,
King of
Bashan, about 1450 B. C. The Arundelian marbles place the use of iron in 1370 B. C., and other authorities go back to 1537 B. C. These corroborate the iron bedstead of Og. Extremes meet, and we have lately revived the use of the material first recorded as used for that purpose.
Moses mentions an iron furnace 1490 B. C., and Job speaks of iron as “taken out of the earth.”
Gold,
silver, and copper, and alloys of the last, were, no doubt, used before iron, and it would be reasonable to expect that such would be the case, as they are so readily obtained by simple metallurgic operations, while iron is more refractory.
The existence and uses of iron among the ancient
Egyptians are pretty well proved by the paintings, in which the iron or steel knives and sickles are distinguished from the bronze by the color; one being blue, the other a reddish-brown.
In
Dr. Abbott's collection, now in the possession of the New York Historical Society, are the following articles of iron, stated by the doctor to be of undoubted authenticity.
They were found at
Thebes:—
Iron helmet, neck-guard, and breast-plate of scale armor, with the name of Shishak, who invaded Judea 971 B. C.
An iron spatula, iron arrow-head, warrior's flail with iron studs, and some emblematic articles of iron.
The ancient iron mines of the Egyptians have been lately discovered by English explorers.
The process was wasteful, and the slag contains 53 per cent of iron.
The sites are in the vicinity of
Mt. Sinai, and it is proposed to work over the
debris of the former workings.
Of the first use of iron in
Egypt,
Wilkinson says, we have no certain record.
His surprise at the execution of the sculptures is very natural, but he does not appear to have estimated the character of the alloys of copper and tin, some of which are very hard.
(See alloy; bronze.) Belzoni discovered an iron sickle-blade beneath a granite sphinx at
Karnak.
Colonel Vyce found an iron blade imbedded in the great pyramid.
Layard found a steel cross-cut saw, and other articles of iron, at Nimroud; the saw is now in the British Museum.
The butchers of
Thebes and
Memphis had steels slung from their belts.
At
Babylon the stones of the bridge across the
Euphrates, built by
Nitocris, were cramped by bands of iron set in lead.
Thucydides says the blocks of the walls of the Pireus were fastened in the same way.
Theseus, who ascended the throne of
Athens 1235 B. C., was buried with a bronze sword and spear.
Some have dated the use of iron in
Greece at 1406 B. C., but Hesiod makes it later.
Homer generally speaks of bronze arins, but mentions iron.
We learn from the “Iliad” that at the time of the siege of
Troy (1184 B. C.) iron was used in making axes, shipwrights' tools, axles for chariots, plowpoints, sheep-hooks, and some other
agricultural implements. “As the smith plunges the loud-hissing axe into cold water to temper it, for hence is the strength of iron,” etc., shows clearly that the writer or compiler of the “Odyssey,” whom we are content to call
Homer, lived in a time when iron and steel were forged and tempered.
About 500 B. C., and thereafter, steel was imported into
Greece from the Chalybes, a people inhabiting the shore on the southeast of the
Black Sea, and the use of bronze for weapons terminated soon after.
Marathon was fought 460 B. C. The steel was called Chalybian, and we retain the name in connection with waters, as
Chalybeate springs.
In
Asia the Chalybes were noted for their works in iron, from which they obtained great profits. — Xenophon,
Anab.
Aristotle mentions that their arenaceous ores were washed, and he also partially describes the operation of making wootz in
India;
Diodorus Siculus says that in the island of Ethalia the ores were roasted and broken fine before melting.
It was
wrought-iron that was produced and employed, and not
cast-iron, which is a comparatively recent production, and it is probable it was all obtained, by a primitive direct process, from rich and easily reducible ores.
The early means for the reduction of iron from the ore were small furnaces with cold blast, in which rich ore was heated in contact with incandescent charcoal, the viscid mass being hammered to remove earthy impurities.
This plan is yet practiced in
India,
Africa, Malaya, Madagascar, and forms the
“Mass of iron, shapeless from the forge,” offered by
Achilles as a prize at the funeral games of
Patroclus, recorded in
Homer's twenty-third book of the “Iliad.”
Dr. Livingston refers to the iron-smelting furnaces of the tribes encountered in his “Expedition to the Zambesi.”
The articles produced by these peoples are hammers, tongs, hoes, adzes, fish-hooks, needles, and spear-heads.
King Porus presented to
Alexander the
Great a wrought bar of laminated steel, for which
Damascus was subsequently so famous that it is known as Damascene.
One of the most remarkable forgings in the world, if it be one, is the wrought-iron pillar within the precincts of a mosque near
Delhi.
It is a shaft with a capital 22 feet high above ground, and a greater length below.
Its probable weight is over 38,000 pounds. It has an inscription in Sanscrit, which records that it was erected by King Dhava of the Hindoo faith.
The character of the Sanscrit inscription, according to the
English linguists of Hindostan, indicates a period at about A. D. 400.
See forging.
The examples cited from the writings of
Moses, Hesiod, and
Homer, the attestation of the recovered implements from
Egypt and
Nineveh, and the
Egyptian paintings, render it useless to cite the facts within the notice of the gossiping and credulous Pliny, who professes to give the early history of the metal.
Palestine,
Asia Minor, Scythia,
Elba, and
Spain were each celebrated in their time for the production of iron.
From
Iberia the art spread to
Gaul, and from the latter, probably, to
Germany.
An army of Gauls was defeated by the Romans, 222 B. C., chiefly because the swords of the former bent after a blow or two, and required straightening by the foot, while the superior metal of the Romans stood the brunt.
Strabo mentions that one of the exports of Britain was iron; the bold islanders met their invaders with scythes, hooks, broadswords, and spears of iron.
The arrival of the Romans and the introduction of artificial blast, which the Romans had derived from their Eastern neighbors, gave a great impulse to the iron works of
England.
Under
Adrian, A. D. 120, a fabrica or military forge was established at
Bath, in the vicinity of iron and wood.
During the
Roman occupation of
England, some of the richest beds of iron ore were worked, and the
debris and cinders yet exist in immense beds to testify to two facts: one, that the amount of material worked was very great; the other, that the plans
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adopted were wasteful, as it has since been found profitable to work the cinder over again.
During the
Saxon occupation the furnaces were still in blast, especially in
Gloucestershire.
The early
Norman sovereigns were so intent upon skinning the Jews and the Saxons, that it became dangerous to succeed in any business, success being an invitation to the barons to plunder.
Accordingly, we find in the time of King John that iron and steel were imported from
Germany.
The business lumbered along for some centuries, the government tinkering at it now and again, the exportation being prohibited in the fourteenth century, and the importation of iron in the fifteenth century.
The direct method of obtaining wrought-iron from the ore prevailed until the commencement of the fifteenth century, but then gradually gave way to a less direct process, but one more convenient when handling large quantities.
Blast-furnaces, operating by the aid of strong blast, to
melt the iron and obtain
cast-iron, which is carbureted in the process, were in use in the neighborhood of the
Rhine about A. D. 1500.
A second process in a
forge-hearth was used to eliminate the carbon and other impurities, and the result is
wrought-iron. The
puddling-furnace was invented more than 250 years afterward.
In the sixteenth century (1590), we find a notice of a mill for slitting iron into bars for smiths' use by
Godfrey Bochs.
The change from the use of wood coal to that of mineral coal was only accomplished in
England after a great many futile attempts.
In the reign of Elizabeth, blast-furnaces were of sufficient size to produce from two to three tons of
pig-iron per day by the use of charcoal.
In the small works, the iron was made malleable before being withdrawn from the blast-furnace, and in larger works was treated by the refinery-furnace.
Wood becoming scarce, and a number of furnaces having gone out of blast, in 1612,
Simon Sturtevant was granted a patent for thirty-one years for the use of pit-coal in smelting iron.
Failing in his proposed plans, he rendered up his patent the following year.
The patent was granted in 1613 to
John Ravenson, who also failed, and resigned his patent, which was again and again granted to succeeding inventors and adventurers who believed themselves possessed of the means and knowledge for accomplishing the object.
In 1619 the patent came into the hands of
Dudley, who at the age of twenty left Oxford University to take charge of his father's furnaces at Pensnet, in Worcestershire, and who succeeded in producing three tons of iron per week in a small blast-furnace by the use of coke from pit-coal.
The parties who yet possessed plenty of wood, and with whom the production of iron was fast becoming a monopoly, urged the charcoal-burners to destroy the works of
Dudley, which was done.
Dudley's patent was granted for thirty-one years, which would bring it to 1650, the time of the Protectorate, when
England had a ruler fit to succeed Queen Bess.
The celebrated statute of King James, limiting the duration of patents to fourteen years, was passed in 1624.
From the circumstance that
Dudley petitioned
Oliver Cromwell and Council for a renewal of the term, two things are evident: one, that he had pursued the scheme and anticipated or had achieved success; the other, that the limitation of his patent from thirty-one to fourteen years had not been enforced or had been revoked.
Dudley charges that the extension of his term was refused by the influence of favorites of the
Protector, who wished to share in his profits, and on his refusal defeated his application for extension.
It is likely that
Dudley only received a moderate remuneration for his pains, as no one seems to have taken any interest in the business after it was thrown upon the public by the expiration of his patent.
Iron of poor quality continued to be made in districts where wood was scarce, and of good quality from charcoal in places where the forests yet remained.
The demand for iron continuing to grow, — a natural effect of advancing civilization, — iron was exported from
Sweden and
Russia in large quantities and of excellent quality.
The forests of these countries gave them a natural advantage over
England, whose woods had by this time become thinned out, so that the use of wood for iron smelting had been forbidden by act of Parliament in 1581, within twenty-two miles of the metropolis, or fourteen miles of the
Thames, and eventually was forbidden altogether.
The art of making iron with pit-coal, and of casting articles of iron, was revived by
Abraham Darby, of Colebrook dale, about 1713, and was perseveringly followed, although it was but little noised abroad.
In the
Philosophical Transactions for 1747 it is referred to as a curiosity.
Certain parties had attempted to smelt iron in clay pots exposed in a furnace, resembling that used for glass, to the flame of a pit-coal fire, expecting to procure the iron by tapping the pots.
The scheme, which might have answered with a more tractable material, failed in the case of the iron ore.
Tinning of iron was introduced from Bohemia in 1681.
The extension of the iron manufacture dates from the introduction of the steam-engine, which increased the power of the blast, and the blowing engines driven by manual, horse, or ox power were superseded by engines.
The dimension of the blast apparatus was increased from time to time, and about 1760 coke was commonly used in blast-furnaces.
In 1760
Smeaton erected at the Carron works the first large blowing cylinders, and shortly after
Boulton and
Watt supplied the
steam-engines by which the blowers were driven.
Peter Onions, in his patent of 1783, described the
rationale of the puddling process; and
Henry Cort, of
Gosport, in 1784, made it practicable, and added grooved rolls, by which the puddled bar was drawn.
Neilson, of
Glasgow, introduced the hot blast in 1828.
Aubulot, in
France, in 1811, and
Budd, in
England, in 1845, heated the blast by the escaping hot gases of the blast-furnace.
The
Calder works, in 1831, demonstrated the needlessness of coking when hot blast is employed.
Experiments in smelting with anthracite coal were tried at
Mauch Chunk in 1820, in
France in 1827, and in
Wales successfully by the aid of
Neilson's hot-blast ovens in 1837.
The experiment at
Mauch Chunk was repeated, with the addition of the hot blast, in 1838, 1839, and succeeded in producing about two tons per day. The Pioneer furnace at
Pottsville was blown July, 1839.
The first iron-works in
America were established near
Jamestown, Virginia, in 1619.
In 1622, however, the works were destroyed, and the workmen, with their families, massacred by the Indians.
The next attempt was at
Lynn, Massachusetts, on the banks of the
Saugus, in 1648.
The ore used was the bog ore, still plentiful in that locality.
At these works
Joseph Jenks, a native of
Hammersmith, England, in 1652, by order of the Province of
Massachusetts Bay, coined silver shillings, sixpences, and threepences, known as the “pine-tree coinage,” from the device of a pine-tree on one face.
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Of the special processes for treating and purifying, a few may be cited:—
Smelting by blast with charcoal, pit-coal, and coke, and with the addition of limestone or shells as a flux, have been noted.
See
supra; also blastfurnace.
Puddling and
boiling, somewhat similar operations for burning the carbon of
pig-iron and eliminating other impurities, are considered under those heads.
See also decarbonizing-furnace; reducing-furnace; malleable iron; Bessemer process; forge, etc. See list under metallurgy.
Steel processes are considered under steel. See also Bessemer process; convertor; cementation-furnace, etc.
A process for decarbonizing molten cast-iron by applying an air-blast in the hearth of a blast-furnace was invented by
C. Shunk.
Kelly patented in the
United States, in 1857, a mode of decarbonizing molten crude cast-iron by running it into a cupola or vessel, separate from that in which it was melted, and blowing through it from the bottom a blast of air, so as to burn out the excess of carbon, — the blast being strong enough to furnish rapid combustion of the carbon, and thereby retain the temperature and fluidity of the molten metal until sufficiently refined, without the use of other fuel.
Bessemer worked as an original inventor in the same line, and much improved the process in general and in detail.
Holley gave it its American form.
See Bessemer process.
The process of decarbonizing the molten iron by addition of manganese is found in
Reynolds's English patent, about 1800.
Mushet's patent consisted in the introduction of manganese or other highly oxidizable metals, during the process of melting the crude iron, for the purpose of detaching and removing oxidized substances.
Krupp uses spiegeleisen.
Schmit, of the
Troy Bessemer works, recommends ferro-manganese in small quantities and in solid pieces, as a recarburizer.
Clay's process of making wrought-iron direct from the ore (
English, 1843) consists in sifting rich ground ore, mixed with 4/10 weight of coal, into the chamber of a furnace where it is puddled and balled; after this it is shingled and rolled in the ordinary manner.
Jameson's process consists in exposing the calcined and crushed ores in a series of deoxidizing chambers, where it is exposed to the heat of the burning gases which come from the furnace below.
It is pushed from the floor of one chamber to another, and in the last chamber is exposed to hydrogen generated by the decomposition of a jet of steam injected upon it to aid in ridding it of sulphur and phosphorus.
Thence to the charcoal bed and refining chamber, where the
loop is formed, and whence it is taken to the hammer.
Henderson's process for the manufacture of ironsteel (patents, 1870) embraces the use of fluor-spar and titaniferous ores, and treating crude ores by fluorides and oxides.
The Ellershausen process consists in the conversion of crude cast-iron into wrought-iron by the admixture of granulated iron ore, a layer of molten iron, and a sprinkling of powdered ore, alternating in molds.
These blooms are put in a reverberatory, puddled, squeezed, and rolled.
Bessemer has patented in
England a mode of applying to the decarbonization of iron, nitrates, chlorates, and other salts, which evolve oxygen when heated.
By
Blair's process, patents Nos. 126, 923, 924, 925, of 1872, the oxides of iron are subjected, in contact with solid carbon for a certain time, to a uniform red heat, the access of other oxygen during the process being prevented.
By this means the oxygen leaves the iron and unites with the carbon, passing off in a gaseous state, while the iron remains, being reduced to a metallic state as iron sponge.
The metallic iron thus obtained is, however, in a very sensitive condition while hot, and in that state absorbs oxygen with great avidity; but, if cooled before being brought into contact with the atmosphere, it does not readily re-oxidize.
After reduction, the iron sponge retains the shape of the ore from which it is derived, but somewhat expanded in bulk, and with very marked loss of weight.
It has a spongy texture; is readily sectile; is easily indented by the finger-nail; chews like lead between the teeth, and polishes quickly to a silvery luster.
Its color, unless influenced by some coloring matter accidentally present in the ore, is grayish, varying from blackish to a clear lead-color.
When powdered and burned in the open air it sparkles brilliantly, as does iron burned in an atmosphere of oxygen.
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Angle, bar, girder, and rail irons. |
Taylor describes a method of making cast-iron from oxides of iron by reducing magnetic iron ores
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to powder and separating the iron oxides therefrom by magnets, and preparing and uniting the same for use in the furnace.
See steel. Also, and much better, see
Percy's “Metallurgy, iron and steel,”
London, 1864.
2. An instrument or utensil of iron.
A
box-iron, flat-iron, smoothing-iron, sad-iron, or
Italian-iron is a form of heated instrument for smoothing damped clothes, starched or otherwise.
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Angle, bar, girder, and rail irons. |
The
iron-heater is a piece of metal or wire heated in the fire and placed in an urn,
box-iron or
Italianiron, to heat it.
The
iron-holder is a pad upon the handle to protect the hand; or is a ring or tripod to stand the iron upon temporarily.
Tailors' and
hatters' irons are forms of smoothingirons adapted to the uses of the said operatives.
A tailor's iron is known as a
goose.
A
plane-iron is the bit or cutting portion of a joiner's plane.
3. The iron portion of a thing, as a
boom-iron, or
pump-iron; a
clip of a single-tree; the
plow-irons, the iron portions of a plow, etc.
